What Is a Planet?

The exhibition addresses the most compelling questions in astronomy, like why Pluto is no longer a planet, in a fun, dynamic way, and demonstrates how new approaches and perspectives in science can help change our view of the Universe. In the exhibit, guests explore artifacts from the Adler’s collections that show how “planets” aren’t what they used to be, witness how astronomers and the media reacted to Pluto’s reclassification in 2006, and discover what it requires to be a planet today.